Added ConnectionTimeObserver to provide a way to calculate times between the different stages.

The ConnectionTimeObserver saves the state of the client and the time when the client state changes. The delta times can be accessed through GetStateTransitionDelay and a start and end state.

BUG=

Review URL: https://codereview.chromium.org/1238343002

Cr-Commit-Position: refs/heads/master@{#341232}
13 files changed